Parry’s gentian

Gentiana bracteosa Greene; Pneumonanthe parryi (Engelmann) Greene

Herbs perennial, 1–3.5(–4.5) dm, usually glabrous, occasionally minutely puberulent in lines on stems only. Stems 1–7(–14), terminal from caudex, decum­bent to erect. Leaves cauline, ± evenly spaced; blade ovate, 1.5–4 cm × 8–21 mm, margins not ciliate, apex obtuse; involucral leaves wider than cauline, ascending and conduplicate, partially enveloping base of inflorescence. Inflorescences 2–7-flowered heads or occasionally solitary flowers, occa­sionally with additional flowers in 1 or 2 distal axils. Flowers: calyx 10–20(–27) mm, lobes linear to lance­olate, (1–)4–8 mm; corolla deep blue or violet-blue, cam­panulate, open, 33–50 mm, lobes spreading, obovate, 4–9 mm, free portions of plicae divided less than 1/2 their length into 2–5 triangular segments threadlike only toward apex; anthers distinct. Seeds not winged.

Flowering summer–fall. Mountain meadows; 1800–3900 m; Ariz., Colo., N.Mex., Utah, Wyo.

Reports of Gentiana parryi outside the range indicated here have been based on specimens of G. calycosa or G. affinis (studies for this flora). Because of its restriction to high altitudes, populations of G. parryi are widely scattered, especially in the southern part of its range.

Gentiana parryi has sometimes been included in G. calycosa and less often in G. affinis, but its larger, conduplicate involucral leaves, which are more or less sharply differentiated from the distal cauline leaves and largely envelop the calyces, give G. parryi an aspect distinctly different from that of either G. calycosa or G. affinis. Biometric studies by J. R. Spence (unpubl.) have supported its recognition as a species. As noted by N. H. Holmgren (1984b), these species also differ in anther length, which is 3.5–5 mm in G. parryi and 1.6–3.2 mm in G. calycosa and G. affinis. In the Rocky Mountains of central Colorado, G. parryi and G. affinis appear especially well differentiated. Where the ranges of G. parryi and G. calycosa approach each other in the Intermountain Region, G. parryi usually grows in drier habitats than G. calycosa. The distinctive involucre of G. parryi is less well developed in some Arizona plants otherwise identifiable as this species, which should be given further study.